Transmitting data wirelessly is generally known in the art. In some applications, data may need to be sent to multiple devices concurrently over a wireless link. Protocols have been designed to achieve such concurrent wireless data transmission. One of the common implementations of those protocols is the broadcast/multicast schemes where the same data is sent to all devices simultaneously. In such protocols, no feedback is provided from the devices to the data source. Another way for sending the data is to designate one of the devices as a primary device and one or more other devices may be designated as secondary device(s). In those protocols, data may be sent to the primary device wirelessly first; and after receiving the data, the primary device may forward the data to the secondary device(s). In addition to the data, the primary device can send additional control or synchronization information to the secondary device(s).
Wireless earbuds are one example application that uses concurrent wireless transmission protocol mentioned above. A pair of wireless earbuds typically includes a right earbud and a left earbud. Typically, wireless earbuds employ Bluetooth to receive audio data from a master device—for example, a smartphone, a tablet, a laptop or a desktop computer. Either the right or left earbud is designated as the primary earbud that will receive data from the master device and forward the data to the other earbud.